Gas turbine engine rotors, such as fan, compressor and turbine rotors, can be balanced by removal of material. The material removal process usually involves milling at least one groove or notch into a surface of the rotor, checking the unbalance and then further removing a small amount of material from the notch(es) (typically with a hand held tool) to perfect the balance. These notches may create high stress areas in the rotor. Typically a minimum radius is required at the ends of the balancing notches to keep stresses to an acceptable level. However, the final manual material removal process is not controlled as well as milling and may possibly result in the creation of further stress concentration zones in the form of small undulations at the surface of the notches or in the form of an undercut at the ends of the radius. To control the surface finish and minimize or attempt to correct these surface defects, a polishing operation may then be conducted. However, it is known that polishing will remove beneficial compressive stresses on the surface that are usually present from milling or turning operations.
Accordingly, there is a need for improvements.